An Instant Messaging (IM) system has a wide range of applications. The typical Instant Message system includes a client side and a server side. A user typically logs in a single login server that serves numerous clients. During the IM session, if the login server becomes unavailable (for example, hardware failure or shutdown due to maintenance), the sessions between the login server and its clients are lost and the users are redirected to the login interface and prompted to login again. The users connected to the login server experience service interruptions since they must repeat the login process and re-establish new IM sessions with a different login server. Further, when all the disconnected clients retry to log in to another login server simultaneously, excessive load pressure may be imposed on the login server.